Instruction22t.java revision 5867263eb588f4671400895d1e6b01c01535061b 
1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2009 Ben Gruver
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29package org.jf.dexlib.Code.Format;
30
31import org.jf.dexlib.Code.Instruction;
32import org.jf.dexlib.Code.Opcode;
33import org.jf.dexlib.Code.OffsetInstruction;
34import org.jf.dexlib.DexFile;
35import org.jf.dexlib.Util.NumberUtils;
36import org.jf.dexlib.Util.Output;
37
38public class Instruction22t extends Instruction implements OffsetInstruction {
39    public static final Instruction.InstructionFactory Factory = new Factory();
40
41    public static void emit(Output out, Opcode opcode, byte regA, byte regB, short offC) {
42        if (regA >= 1 << 4 ||
43                regB >= 1 << 4) {
44            throw new RuntimeException("The register number must be less than v16");
45        }
46
47        if (offC == 0) {
48            throw new RuntimeException("The offset cannot be 0.");
49        }
50
51        out.writeByte(opcode.value);
52        out.writeByte((regB << 4) | regA);
53        out.writeShort(offC);
54    }
55
56    private Instruction22t(Opcode opcode, byte[] buffer, int bufferIndex) {
57        super(opcode, buffer, bufferIndex);
58
59        if (getOffset() == 0) {
60            throw new RuntimeException("The offset cannot be 0.");
61        }
62    }
63
64    public Format getFormat() {
65        return Format.Format22t;
66    }
67
68    public byte getRegisterA() {
69        return NumberUtils.decodeLowUnsignedNibble(buffer[bufferIndex + 1]);
70    }
71
72    public byte getRegisterB() {
73        return NumberUtils.decodeHighUnsignedNibble(buffer[bufferIndex + 1]);
74    }
75
76    public int getOffset() {
77        return NumberUtils.decodeShort(buffer, bufferIndex + 2);
78    }
79
80    private static class Factory implements Instruction.InstructionFactory {
81        public Instruction makeInstruction(DexFile dexFile, Opcode opcode, byte[] buffer, int bufferIndex) {
82            return new Instruction22t(opcode, buffer, bufferIndex);
83        }
84    }
85}
86